So what would be different in the Narutoverse if Obito remained good?
Madara would have probably been dealt with.
Minato, Kushina, Iruka's parents, Sarutobi's wife and many other nameless ninjas would be alive.
Uchiha would not have been slaughtered.
Akatsuki wouldn't be formed.
Asuma would still be alive.
Sasuke would have remained good.
Naruto would not be a Jin and maybe nowhere near as determined to become as strong as he is.
Kurama may have remained angry.
Gaara may have never become good.
Jiraiya might still be alive.
The third might not have died as Orochimaru would have faced off against Obito instead (chunin exams).
Shisui might still be alive.
The ninja alliance would probably have not been formed. Undeniably the biggest step towards a world of peace.
Gaara may not have been Kazekage.
I'm sure I'm missing some. Feel free to add!